It’s been Day #10 of 2023 with a high temp at or above 80 degrees Tuesday—The high of 85 comes in 12 degrees above the normal of 73 degrees.

Big changes loom—A strong cold front sweeps across the area, having traveled the length of Lake Michigan, reaching the city proper around 7 a.m. Wednesday morning

Fronts like this, with a sprawling Canadian high pressure behind it, develop quite a “head of steam” while racing south the length of Lake Michigan. The strong “NNE” winds behind such a front hit fast and hard and promise a Wednesday with gusty NNE winds which will churn Lake Michigan.

“NNE” wind gusts of 20 to 30 mph are likely Wednesday building waves of 7 to 9 feet. coming into the Chicago shoreline. Small craft advisories kick in at 7 a.m. CDT Wed and run through 7 a.m. Thursday.

NNE winds travel over chilly water all 280 miles of Lake Michigan on their way southward which sets up much cooler temps along the lakeshore. While inland highs Wed are to come in 15 to 20 degrees lower than today, shoreline temps reductions will be even sharper with daytime highs on area beaches holding to the 50s—representing a a 25-30 degrees 24 hour temp drop.

A blocking pattern develops which slows the progression of U.S. weather system movement. This means the high pressure which comes in with such meteorological “fanfare”—-i.e. wind, waves and a big temp drop—Wednesday is to remain our dominant weather feature in Chicago through the Memorial Day weekend and into next week. This shuts down rain chances until the middle of next week—not good news given the flash drought situation which is developing here with the incredibly lackluster May precipitation we’ve seen—just 0.42″ which comes in at only 13% normal and follows a dry April which saw only a little over half the normal amount of rain.

Even though rains have arrived in western Canada helping firefighters in that areas and dampening the fires there, the smoke those fires have already produced will ride in Chicago’s airspace Wed—so skies will grow hazier than Tuesday and may remain that way into Thursday—even though cloudiness itself will be very limited.

As the high pressure sits here, the pressure gradient is to weaker]n. Thus the transport of chilly air down the lake will slow and come to an end as the week progresses allowing the air mass to begin warming in place. It’s that warming which suggest high temps are likely to return to near 80 inland Saturday—upper 60s along the lake and on area beaches—to the low 80s Sunday and mid 80s Memorial Day (Monday) itself.

And next week is to be dominated by mid to upper 80s if not within striking distance of 90 on at least a couple of days sending the weekly average temp 9 degrees higher than this week and 7 degrees above normal.

June 2023 gets underway next Thursday and current forecast trends suggest a warmer than normal open to the month—though cooling lake breezes may be a part of the Chicago weather scene not only this week—but through next week as well.


TONIGHT: Only a few clouds, mild with fairly light winds most of the night. Winds shift north and increase early Wednesday morning. Low 56.

WEDNESDAY: A good deal of hazy sunshine but windy and markedly cooler—nowhere more so than along Lake Michigan. The haze is the product of smoke off west Canadian wildfires. Winds gust 20 to 30 mph and temps reach levels 15 to 25-deg cooler than Tuesday. High 68—but 50s lakeshore and beaches,

WED NIGHT: Partly cloudy, breezy and cooler. Low 47—6-deg below normal.

THURSDAY: Partly sunny, breezy and cooler than typical this time of year. High 71—but low 60s lakeshore,

FRIDAY and SATURDAY: Generous sunshine with gradually warming temps and less wind, except for easterly lake breezes on the Lake Michigan shoreline. High Friday 74. Saturday’s high 79. Beach temps ranging from the mid 60s to low 70s each day.

SUNDAY: Partly sunny and warmer. High 83—but low to mid 70s beaches.

MONDAY (Memorial Day) and TUESDAY: Partly sunny with the warming continuing and day to day lake breezes along Lake Michigan. High Monday 86; Tuesday’s high 88—but 70s along the lake.